Fuel supply system

Abstract

A fuel supply system is proposed for mixture-compressing internal combustion engines having externally supplied ignition. The fuel supply system includes an air intake tube delimited by an air filter, the air intake tube having a conical section downstream of which an arbitrarily actuatable throttle device is disposed. Associated with the conical section of the air intake tube is an air bypass line in which an air flow rate meter provided with a temperature-dependent resistor is disposed. The quantity aspirated by the engine is determined by this air flow rate meter. A fuel injection valve is disposed in such a manner that on one side it protrudes into the interior of the air filter and on the other side, with a slender mouthpiece, it protrudes approximately through the conical section. The fuel can be injected into the gap between the throttle device and the air intake tube wall by means of this mouthpiece. The fuel supply system according to the invention has a very low structural height.

What is claimed and desired to be secured by Letters Patent of the United States is: 
     
       1. A fuel supply system for mixture-compressing internal combustion engines with externally supplied ignition comprising an air intake tube, an air filter positioned relative to said air intake tube, said air intake tube having a venturi-like section, an arbitrarily actuatable throttle device in said intake tube downstream of said venturi-like section, a fuel injection valve upstream of said throttle device for injecting toward said throttle valve a quantity of fuel corresponding to the quantity of air aspirated by the engine, an air bypass line connected to said venturi-like section of said air intake tube, an air flow rate meter in said air bypass line and further that said injection valve includes a portion arranged to protrude into said air filter upstream of said venturi-like section, and said injection valve comprises a slender mouthpiece which extends through said venturi-like section so that fuel can be ejected upstream of said throttle device downstream of said venturi-like section. 
     
     
       2. A fuel supply system as defined by claim 1, characterized in that a temperature-dependent resistor serves as the air flow rate meter, the temperature and resistance value thereof being regulated in accordance with the aspirated quantity of air. 
     
     
       3. A fuel supply system as defined by claim 2, characterized in that said throttle device has a periphery which can be brought into a point of contact with paid intake tube and fuel can be injected toward said point of contact. 
     
     
       4. A fuel supply system as defined by claim 3, characterized in that said injection valve is electromagnetically actuable.